For Novak Djokovic, his loss to Andy Murray in the 2012 U.S. Open final Monday evening was the proper end to a wholly disappointing ATP season.

After one of the most dominating seasons in tour history last year, Djokovic's 2012 campaign was one of regression. There is no sane person alive that would say the 25-year-old Serb had a bad season. There is no planet in the solar system where making three Slam finals and winning one can be considered bad.

It was, for lack of better term, just a bummer.

Instead of repeating Roger Federer's absolute evisceration of the tennis world from 2004-2006 (where the Swiss star won no fewer than 11 tournaments or two major championships), Djokovic simply reverted to the player he was pre-2011. A great player, but not deserving of the all-time discussion quite yet.

Nevertheless, his loss Monday—and his disappointing 2012 campaign as a whole—are necessary steps in the evolution of his story.

The dirty little secret about Federer's reign all atop the tennis world is that it wasn't truly compelling whatsoever. Awe-inspiring, majestic, transcendent and nearly every other superlative you can think of could fit the description.

Exciting? Absolutely not.

That's why the constant comparisons to (and his eventual friendship with) Tiger Woods seemed so appropriate. Here were two singular forces annihilating the world's most popular individual sports, and no one seemed to pack the gravitas to compete on a regular basis.

Woods in his prime never found that rival. You could argue Phil Mickelson, but it's undeniable that Tiger's pseudo rivalry right now with 23-year-old Rory McIlroy is more compelling.

Federer, however, found Rafael Nadal—a man not only the Swiss star's talent equal, but one who got boundlessly better every season on tour.

Djokovic was seemingly about to enter an era of Woodsian/Federerian dominance heading into Monday night.

With Federer closing in on 32 years old (geriatric for a tennis player) and Nadal's future uncertain due to injuries, it seemed unlikely that anyone would step to the plate. In fact, coming into his semifinal match against David Ferrer, I called it an "empty bracket."

That's why Murray's victory was so necessary. After fighting against the glass ceiling for what seemed like forever, the 25-year-old Scot finally broke through, coming out victorious in tennis' last two big-time tournaments and beating Djokovic en route both times.

And it's not like Djokovic made it easy at Flushing Meadows. After utterly failing early, losing the first set and falling behind 4-0 in the second, the Serb made a run at an epic comeback. Djokovic nearly came back to win the second before taking the third and fourth sets, getting more animated every step of the way.

He was out of gas by the fifth set. But what you saw Monday night was not just a nearly five-hour tennis match. Instead, it's what should be the beginning of tennis' new great rivalry.